1. Field of the Invention
The invention relates to a process for preparing OH-terminal organopolysiloxanes having diorganosiloxy units and Si—H groups.
2. Description of the Related Art
EP 967236 A describes the preparation of hydromethyl-polysiloxanes with trimethylsilyl end groups in a two-stage process from methyldichlorosilane, trimethyl-chlorosilane and water.
JP 07330904 A describes a process for preparing OH-terminal organohydropolysiloxanes by ring-opening copolymerization of cyclic hydrosiloxane and cyclic siloxane.
DE 3126343 A describes the preparation of OH-terminal organohydropolysiloxanes by cohydrolysis of methyl-dichlorosilane, dimethyldichlorosilane and water. In the course of preparation and storage of the products, hydrogen is eliminated, which gives rise to branches and leads to gelation of the products. The uncontrolled condensation of the terminal Si—OH groups leads to highly viscous products.